U.S. patent application number 10/256186 was filed with the patent office on 2003-04-24 for controlled morphogenesis of copper salts.
Invention is credited to Goebel, Gerhard, Ploss, Hartmut, Simon, Andre.
Application Number | 20030077219 10/256186 |
Document ID | / |
Family ID | 26010258 |
Filed Date | 2003-04-24 |
United States Patent
Application |
20030077219 |
Kind Code |
A1 |
Ploss, Hartmut ; et
al. |
April 24, 2003 |
Controlled morphogenesis of copper salts
Abstract
In a method for preparing copper salts from at least one
cupriferous and one additional reactant, the reactants are used to
prepare micro-emulsions while employing at least one block polymer,
the intermediate products obtained this way are mixed and reacted
together so as to form a micro-emulsion. The preparation of the
starting micro-emulsion as well as the subsequent joint reaction
preferably occur either with ultrasound or in a high-pressure
homogenizer. The copper salts obtained this way exhibit a particle
size of less than 50 nm, preferably 5 to 20 nm and can be adjusted
to specific applications through the appropriate doping of foreign
ions.
Inventors: |
Ploss, Hartmut; (Hamburg,
DE) ; Goebel, Gerhard; (Itzehoe, DE) ; Simon,
Andre; (Hamburg, DE) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 8910
RESTON
VA
20195
US
|
Family ID: |
26010258 |
Appl. No.: |
10/256186 |
Filed: |
September 27, 2002 |
Current U.S.
Class: |
423/604 |
Current CPC
Class: |
C01G 3/02 20130101; C01G
3/00 20130101; C01P 2004/64 20130101; B82Y 30/00 20130101; C01P
2006/12 20130101 |
Class at
Publication: |
423/604 |
International
Class: |
C01G 003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 28, 2001 |
DE |
101 48 145.4 |
Oct 16, 2001 |
DE |
101 51 060.8 |
Claims
We claim:
1. A method for preparing copper salts from a cupriferous reactant
and an additional reactant, comprising the steps of: preparing a
first micro-emulsion of the cupriferous reactant and a first block
polymer; preparing a second micro-emulsion of the additional
reactant and a second block polymer; combining the first and second
intermediate micro-emulsions to form a final micro-emulsion;
reacting the cupriferous reactant and the additional reactant in
the final micro-emulsion to produce a copper salt characterized by
a specific surface area of at least 100 329 m.sup.2/g.
2. A method for preparing copper salts according to claim 1,
wherein: the step of preparing the first micro-emulsion; the step
of preparing the second micro-emulsion; and the step of combining
the first and second micro-emulsion to form the final
micro-emulsion, each further comprise applying energy to the
micro-emulsions from a means selected from a group consisting of an
ultrasonic agitator and a high-pressure homogenizer.
3. A method for preparing copper salts according to claim 1,
wherein: the first block polymer and the second block polymer are
substantially identical block polymers.
4. A method for preparing copper salts according to claim 1,
further comprising the step of: reacting the copper salt with a
strong base to produce an alkaline copper compound.
5. A method for preparing copper salts according to claim 4,
wherein: the soluble copper salt is selected from a group of copper
salts consisting of copper chloride (CuCl.sub.2) and copper nitrate
(Cu(NO).sub.3) and the strong base is sodium hydroxide (NaOH).
6. A method for preparing copper salts according to claim 5,
wherein: the step of forming the final micro-emulsion further
comprises forming an intermediate micro-emulsion comprising a
dispersed agglomerate.
7. A method for preparing copper salts according to claim 6,
wherein: the dispersed agglomerate comprises a copper
hydroxide/sodium chloride (Cu(OH).sub.2/NaCl.sup.-) agglomerate and
wherein the step of reacting the cupriferous reactant and the
additional reactant further comprises the steps of reducing
bivalent copper (Cu.sup.2+) to monovalent copper (Cu.sup.+); and
forming copper-(I)-oxide (Cu.sub.2O).
8. A method for preparing copper salts according to claim 1,
wherein the block copolymer comprises at least one material
selected from a group 336 consisting of polyethyleneoxide block
polymer, poly(ethylene-co-butylene)- -b-polyethylenieoxide block
polymer, poly(propyleneoxide)-b-polyethyleneox- ide block polymer
and poly(m-alkyl)(meth)acrylate-b-poly(meth)acrylic acid.
9. A method for preparing copper salts according to claim 1,
wherein the step of combining the first and second micro-emulsion
to form the final micro-emulsion further comprises the step of:
doping the final micro-emulsion with foreign ions.
10. A method for preparing copper salts according to claim 9,
wherein: the foreign ions comprise at least 5 percent by weight of
the final micro-emulsion.
11. A method for preparing copper salts according to claim 9,
wherein: the foreign ions comprise at least one ion selected from a
group consisting of zinc ions, phosphate ions and carbonate
ions.
12. A copper salt composition comprising primary particles, wherein
the primary particles are characterized by an average particle size
of less than 50 nm; and a specific surface area of more than 100
m2/g.
13. A copper salt composition according to claim 12, wherein the
primary particles are characterized by an average particle size of
between about 5 nm and about 20 nm.
14. A copper salt composition according to claim 12, further
characterized by a quantity of foreign ions.
15. A copper salt composition according to claim 14, wherein the
quantity of foreign ions comprises about 5 percent by weight of the
copper salt composition.
16. A copper salt composition according to claim 14, wherein the
quantity of foreign ions is selected from a group consisting of
zinc ions (Zn.sup.2+), phosphate ions (PO.sub.4.sup.3-) and
carbonate ions (CO.sub.3.sup.2-).
17. A copper salt composition according to claim 16, wherein the
quantity of foreign ions comprises about 5 percent by weight of the
copper salt composition.
Description
[0001] The present application hereby claims priority under 35
U.S.C. .sctn. 119 to German Patent Application No. 10148145.4,
filed Sep. 28, 2001, and German Patent Application No. 10151060.8,
filed Oct. 16, 2001, the entire contents of both applications which
are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a method for producing copper salts
from at least one cupriferous and one additional reactant.
Furthermore, it relates to a copper salt that has been produced
pursuant to this method.
BACKGROUND OF THE INVENTION
[0003] The production of crystalline copper salts, such as for
example copper hydroxide (Cu(OH).sub.2), copper-(I)-oxide
(Cu.sub.2O), copper-(II)-oxide (CuO), alkaline copper carbonate
(CuCO.sub.3.times.Cu(OH).sub.2.times.H.sub.2O) or alkaline copper
nitrate (Cu(NO.sub.3).sub.2.times.3Cu(OH).sub.2.times.2H.sub.2O) as
well as mixed salts, such as for example copper oxychloride
(CuCl.sub.2.times.3Cu(OH).s- ub.3) and alkaline copper sulfate
(CuSO.sub.4.times.3Cu(OH).sub.2) generally occurs either through
the oxidative leaching or metallic copper or through a
stoichiometric chemical reaction of soluble copper salts with the
appropriate base (preferably a strong base such as lye) and/or
through consecutive reactions of the created finely dispersed
substances.
[0004] One example for oxidative leaching is the preparation of
copper oxychloride pursuant to the reaction:
4Cu+2CuCl.sub.2+2HCl+{fraction (1/2)}O.sub.2.fwdarw.6CuCl+H.sub.2O
(1)
6CuCl+11/2O.sub.2+3
H.sub.2O.fwdarw.3Cu(OH).sub.2.times.CuCl.sub.2+2CuCl.s- ub.2
(2)
[0005] Examples of chemical reactions of soluble copper salts are
the production of copper hydroxide pursuant to the three methods
below:
Copper Hydroxide Method I
CuSO.sub.4+Na.sub.2PO.sub.4.fwdarw.CuNaPO.sub.4+Na.sub.2SO.sub.4
(3)
CuNaPO.sub.4+2NaOH.fwdarw.Cu(OH).sub.2+Na.sub.3PO.sub.4 (4)
[0006] or
Copper Hydroxide Method II
3Cu(OH).sub.2.times.CuCl.sub.2+2NaOH.fwdarw.4Cu(OH).sub.2+2NaCl
(5)
[0007] or
Copper Hydroxide Method III
3Cu+11/2O.sub.2+3H.sub.2O.fwdarw.3Cu(OH).sub.2 (6)
[0008] Further examples include the production of alkaline copper
carbonate pursuant to the reaction:
2Cu(OH).sub.2+CO.sub.2.fwdarw.CuCO.sub.3.times.Cu(OH).sub.2.times.H.sub.2O-
, (7)
[0009] of alkaline copper nitrate pursuant to the reaction:
4Cu(OH).sub.2+2HNO.sub.3.fwdarw.Cu(NO.sub.3).sub.3.times.3Cu(OH).sub.2.tim-
es.2H.sub.2O (8)
[0010] and the so-called Bordeaux mixture pursuant to one of the
following reactions:
CuSO.sub.4+Ca(OH).sub.2+4CuO.times.SO.sub.3.times.3H.sub.2O.times.3CaSO.su-
b.4 (9)
[0011] (in the case of excess CuSO.sub.4)
CuSO.sub.4+Ca(OH).sub.2.fwdarw.[Ca(OH).sub.2].sub.3CuSO.sub.4
(10)
[0012] (in the case of excess Ca(OH).sub.2)
[0013] The copper salts generated in these reactions usually have a
particle size between about 1 and about 10 micrometers (.mu.m) and
a particle surface area of about 1 to about 10 m.sup.2/g. The
structure of the crystalline material produced will depend upon the
chemical composition and, to a certain degree, upon the production
method utilized. For example, copper hydroxide crystals produced
according to the of the copper hydroxide produced pursuant to
Method II are generally available in a needle shape, while the
crystals of the copper oxychloride produced through oxidative
leaching pursuant described above are generally available in an
octahedron shape.
[0014] The biologically active portion of such copper compounds is
the copper ion, which can be released from these water-insoluble
salts and which is available through a natural, so-called
slow-release process for the medium that is to be protected, e.g.,
plants, wood or water. In the case of fungicidal and bactericidal
applications of such compounds to plants, the respective copper
salt compound is typically sprayed onto the plant's leaf surface to
form a copper salt particle film substantially covering the leaf
surface.
[0015] By reducing the particle size of the copper salt particles,
it is possible to reduce the quantity of copper salt that has to be
applied per leaf surface while at least maintaining the same
effect. One way to achieve this result is by controlling the
production conditions, especially the temperatures and
concentrations of the involved substances. This way the particle
size can be lowered from 50 to about 10 .mu.m, possibly to about 1
to 3 .mu.m. It is thus possible to increase the effectiveness
towards special types of fungi from the existing 80% to 100% or to
main an existing 100% effectiveness towards special fungi while
simultaneously reducing the copper salt dosage rate that is
required per hectare.
SUMMARY OF THE INVENTION
[0016] The present invention provides a method for further reducing
the particle size and/or increasing the effective surface area of
copper salt particles, thereby permitting further reductions in the
quantity of copper salt required to maintain or improve the same
beneficial effects achieved with prior art versions of the same
copper salt. Furthermore it is the object of the invention to
provide a range of copper salts having improved properties for use
in a wide range of applications.
[0017] The invention resolves the first task through a method,
where micro-emulsions are prepared from two reactants while
employing at least one block polymer to obtain intermediate
products. These intermediate products are, in turn, mixed with each
other and reacted together so as to form a final micro-emulsion
comprising the desired copper salt. The production of the starting
micro-emulsions as well as the combination and subsequent reaction
is preferably conducted under the influence of ultrasound or in a
high-pressure homogenizer. The copper salts produced according to
the present invention are characterized by primary particles having
an average size of less than 50 nm, and preferably between 5 and 20
nm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The method according to the present invention may utilizes a
variety of techniques for the production of the micro-emulsions.
Certain of these techniques are already widely employed in the
production of polymer particles and are described in the relevant
literature including, for example, by K. Landfester, M. Willert and
M. Antonietti, "Preparation of Polymer Particles in Nonaqueous
Direct and Inverse Miniemulsions," Macromolecules, Volume 33, 2000,
pp. 2370-76. The method according to the present invention also
involves synthetic block polymers and their chemical reaction in
the form of nano-reactors. Intermediate micro-emulsions are
prepared from the reactants, preferably with ultrasonic agitation
or in a high-pressure homogenizer, while employing a block
copolymer. These intermediate micro-emulsions are, in turn, are
mixed together and subsequently reacted, again preferably under the
influence of ultrasonic agitation or in a high-pressure
homogenizer, whereby each micelle acts as an independent
nano-reactor.
[0019] In this example the invention takes advantage of the
above-described influence of the particle size on the product
properties by making copper salts with particle sizes in the
nanometer range available. In the range of these particle sizes,
characteristic function/property relations are formed both in
living and non-living systems. This size range also corresponds to
certain of the property-determining organizational units of
biological systems.
[0020] The copper salts pursuant to the invention can be produced
in two ways: either through the reaction of soluble salts, for
example CuCl.sub.2 or Cu(NO).sub.3, with bases, preferably strong
bases, and, most preferably, lyes, for generating an alkaline
copper compound, wherein the educts exist as solutions, or through
the use of dispersed agglomerates as an intermediate product, for
example through the reaction of, for example, a solid
Cu(OH).sub.2/NaCl agglomerate, obtained through the micro-emulsion
process according to the present invention, to produce Cu.sub.2O in
a multi-phase reaction that reduces Cu.sup.2+ to Cu.sup.+.
[0021] In the method pursuant to the invention, insoluble copper
compounds comprising the desired composition are created in each
nano-reactor. This type of reaction provides a considerable
advantage of the present invention by making the required quantity
of stabilizing block polymers extremely low. With comparatively
small additive quantities, both minute copper salt particles and
high conversion rates can be achieved. Water-soluble salts, e.g.,
sodium chloride or sodium sulfate, may be used in the
micro-emulsion technique and created during the special chemical
reaction fill in the spaces between drop-shaped agglomerating
formations. The quantity of salt required to obtain this effect
depends on the respective process. Agglomerates characterized by a
size of about 200 nanometers (nm) consist of a multitude of primary
particles characterized by a size range of 5 to 20 nm. Due to their
composition, these agglomerates decompose after application to
render effective the primary particles at the desired application
location.
[0022] Due to their nanometer range particle size, the
water-insoluble copper salts produced pursuant to the present
invention exhibit surprising new properties, which differ
considerably from the corresponding prior art embodiments of these
water-insoluble copper salts whose particle size is in the
micrometer range. Due to these novel properties, new and improved
applications possibilities arise, as do considerable advantages in
a wider field of endeavors, some of which are discussed below.
[0023] In the area of fungicidal and biocide applications, the
biological activity of compositions according to the present
invention, in relation to the application rate required per
hectare, is increased to such an extent that a significant
reduction in the quantity of copper salt applied is possible.
[0024] By applying the copper salts at significantly lower rates,
the release of copper into the environment can be brought closer to
the actual copper consumption of the plants, thereby significantly
reducing environmental pollution concerns.
[0025] In the area of wood treatment applications, copper compounds
that have been produced pursuant to the present invention can
penetrate more easily and more deeply into the wood layers under
treatment due to their quasi atomic size. These improved properties
can eliminate or reduce the need for pressure impregnation while
ensuring prolonged protection against various organisms.
[0026] In other technical applications, the significant increase of
the specific area of the particles produced according to the
present invention, increasing the specific area from typical prior
art values of from 1 to 10 m.sup.2/g to about 400 m.sup.2/g,
results in copper compounds with completely new properties such as
catalytic activity increases measured in orders of magnitude.
[0027] Finally, in the area of anti-fouling (marine) paints, the
use of copper-(I)-oxide particles having typical sizes in the
nanometer range enables the production of anti-fouling paints
having specific and reduced emission behavior of copper ions. Such
paints are considerably more environmentally friendly than the
existing anti-fouling paints.
[0028] Beyond that, the step provided pursuant to the invention for
producing micro-emulsions enables specific doping of the generated
nano-particles with foreign ions. While in conventional chemical
reactions the conversion of each anion or cation represents its own
chemical reaction, which triggers a fractioned product creation and
thus a separation of the individual salts, the method pursuant to
the invention results in substantially even doping. This makes it
possible to adjust secondary properties specifically through the
selection and quantity of foreign ions doped into copper salts
according to the present invention. Although this technique may be
conducted with essentially any anionic or cationic species, zinc,
phosphate and carbonate ions are preferred.
[0029] The formulation of the invented copper compounds in the
nanometer range occurs in the familiar fashion based on the
application purpose.
[0030] The invention is explained in more detail in the following
example.
EXAMPLE
[0031] 50 g of a CuCl.sub.2 solution is emulsified with 1 g to 10
g, preferably 4 g, of a polyethyleneoxide block polymer and an
organic solvent, such as 2,2,4-trimethylpentane, the emulsification
preferably occurring under ultrasound treatment or through
high-pressure homogenization, to form a first micro-emulsion.
[0032] In addition to the 2,2,4-trimethylpentane used, cyclohexane,
rape-seed oil and isopropyl palmitate have been found suitable as
organic solvents.
[0033] The duration of the micro-emulsion preparation is regulated
with turbidimetric methods. In the case of alkaline ingredients, a
specifically scheduled process is preferred to suppress hydrolysis
of the fats. For this example, a reaction time of about 120 seconds
was found to be sufficient.
[0034] Furthermore, 17.5 g of sodium hydroxide was dissolved in 29
ml water and separately micro-emulsified with the block polymer and
solvent system used for the CuCl.sub.2 solution as described above
to form a second micro-emulsion, again preferably under ultrasound
treatment or high-pressure homogenization.
[0035] The first and second micro-emulsions were then combined,
mixed and chemically converted through renewed ultrasound treatment
or high-pressure homogenization.
[0036] The product obtained this way is monodisperse and stable. In
this composition it can be formulated directly into a liquid end
product without further processing. For the preparation of a dry
formulation, the micro-emulsion obtained this way is dried, wherein
this process preferably occurs under vacuum conditions.
[0037] The product produced according to the above Example was then
examined using X-ray diffractometry and scanning electron
microscopy to confirm particle sizes between 10 and 50 nm (nm) and
agglomerate sizes between 100 and 300 nm. The product also
exhibited a high specific surface area (Brunauer-Emmett-Teller
(BET) surface area of 390 m.sup.2/g), which results among other
things in a catalytic activity that is dramatically increased as a
function of the application area.
[0038] The starting product obtained this way can be used for a
broad range of applications, of which some are described in the
following.
[0039] A biological examination of copper hydroxide prepared
pursuant the invented method was performed as described above with
regard to its fungicidal effectiveness on grapevine cultures
(against peronospora) and potatoes (against phytophthora). It was
also shown that, for compositions according to the present
inventions, applications comprising between 4% and 10% of the
quantity of the corresponding prior art copper hydroxide
compositions, were sufficient to achieve the same
effectiveness.
[0040] Similarly, an examination of the treatment of dry wood
revealed that during the immersion of untreated dry wood in a
conventional copper hydroxide suspension, the copper hydroxide was
fixated only superficially; the measured penetration depth was less
than one millimeter. During the immersion of equivalent wood into
the copper hydroxide micro-emulsion prepared pursuant to the
invention, the copper hydroxide was not limited to the surface, but
instead penetrated to a depth of more than 10 298 mm.
[0041] The leaching rate of the product produced according to the
present invention, when used in a standardized anti-fouling ship
paint, differs clearly from the leaching rate of a ship paint with
conventionally produced copper salt. While in the test according to
ISO 15181-1, the leaching rate for an anti-fouling product
comprising conventionally produced copper salt was 2
mg/m.sup.2/day, while the leaching rate for an anti-fouling product
comprising a copper salt produced according to the present
invention was only 0.1 mg/m.sup.2/day.
[0042] Doping the copper salts prepared according to the present
invention with different ionic species can provide additional
advantageous properties. For example, it was found that doping 5 wt
% zinc into a copper salt composition intended for agricultural
applications provided enhanced surface adhesion, as in the case of
plants on leaf and fruit surfaces, thereby increasing the duration
of the plant-protecting effects and also eliminating the expense
and environmental emissions associated with the re-application of
prior art compositions that would be required to provide the same
level of protection.
[0043] Doping the copper salts prepared according to the present
invention with 5 wt % phosphate provides a surface blocking effect
on the created nanometer scale particles. This surface blockage
effect increases the stability of the phosphate doped particles,
thereby increasing the resistance to environmental factors that
would tend to degrade the particles. This increased stability
results in significant increases in the duration of the
effectiveness of a single application of a copper salt composition
according to the present invention.
[0044] Finally, doping copper salts prepared according to the
present invention with 5 wt % carbonate produces a composition
comprising particles whose ability to adhere to surfaces is greatly
reduced, if not completely eliminated. Nano-particles doped in this
manner ran completely together on the surface and formed a larger
particle in the micrometer range. It is contemplated that
nano-particles doped in this manner would be particularly useful in
specialty paints.
[0045] In order to improve the stability of micro-emulsions
prepared pursuant to the invention, basically any block polymers
which comprise both a hydrophobic part and a hydrophilic part may
be used. The block lengths must be adjusted such that an inverse
tenside is created, i.e., a tenside that improves the dispersion of
polar components in non-polar dispersion agents. This means that
the hydrophobic part dissolves in the dispersion agent and the
hydrophilic part interacts with the surface of the starting
product.
[0046] Examples of such block polymers include
poly(ethylene-co-butylene)-- b-polyethyleneoxide,
poly(propyleneoxide)-b-polyethyleneoxide, and poly(m-alkyl)
(meth)acrylate-b-poly(meth)acrylic acid.
[0047] The preferred block polymers have a molar mass of about 3000
g and are of sufficient size and composition to remain relatively
stable.
[0048] In the method pursuant to the invention it is important that
the particles are not completely enclosed with tenside and are
covered only to a small extent with block polymers. The hydrophilic
part of the ten-sides is on the surface of the particles, while the
hydrophobic part protrudes into the dispersion agent like a
porcupine. This low coverage represents an important advantage in
that only low quantities of tenside have to be used. The fact that
block polymers, which are biologically not persistent and thus also
cannot enter into undesirable reciprocal effects with metals in the
ground, can be used for performing the above-described method
should be regarded as another benefit.
[0049] Further, although a number of equivalent components may have
been mentioned herein which could be used in place of the
components illustrated and described with reference to the
preferred embodiment(s), this is not meant to be an exhaustive
treatment of all the possible equivalents, nor to limit the
invention defined by the claims to any particular equivalent or
combination thereof. A person skilled in the art would realize that
there may be other equivalent components presently known, or to be
developed, which could be used within the spirit and scope of the
invention defined by the claims.
* * * * *